Check the input of SecretKey.from_bytes to be non zero

[ChihChengLiang]

Hi @kirk-baird,

In the recent release, the standard disallows zero secret key. Should we also add a non-zero check in the SecretKey.from_bytes method? Or do we intentionally don't do so?

milagro_bls/src/keys.rs

Lines 73 to 77 in 515201c

	pub fn from_bytes(input: &[u8]) -> Result<SecretKey, AmclError> {
	Ok(Self {
	x: secret_key_from_bytes(input)?,
	})
	}

[kirk-baird]

Thanks that's a good point you raise we should reject SecretKey::from_bytes([0; 32]). I'll add that in now and make another release :)

[ChihChengLiang]

Thank you so much Kirk!

[kirk-baird]

I'll make a release when this one gets merged upstream apache/incubator-milagro-crypto-rust#47

[kirk-baird]

Resolved in #41